Nine cases of malignant adrenal cortical tumour treated during the last decade are reported. As in many other series, these rare tumours were predominant on the left side (7/9) and affected mainly adult females (6/!) with a mean age of 44 years. The 8 secretory tumours were revealed by their hormonal effects: endocrine syndrome or arterial hypertension. The single, clinically non-secretory tumour presented as a palpable mass. The most common findings of hormonal exploration undertaken in 8 of the 9 patients were abolition of the cortisol nycthemeral cycle and non-response to dynamic tests. In 8 cases the tumour was demonstrated by intravenous urography, but its location and extension were best shown by CT scans. Two scintigraphies performed with labelled iodocholesterol were positive. All patients underwent complete excision of the tumour: 5 out of 9 had hepatic metastases at the time of surgery. The median survival of the 7 patients who died was 13 months; 6 of these had received Op'DDD (mitotane) post-operatively. Two patients, including one treated with Op'DDD, are still alive after 18 and 32 months respectively, without signs of recurrence.